In TurnKey 11, instead of installing the root filesystem directly to a fixed size partition, we setup LVM by default, and install the root filesystem to a Logical Volume, which may later be expanded, even across multiple physical devices.

Unfortunately, as with anything powerful, to get the most out of LVM you first have to negotiate a learning curve. From the feedback we've been getting it seems that confusion regarding LVM is common with new users, so here's a quick "crash course"...

We can only extend a Logical Volume within the free space of the underlying Volume Group. How much free space we currently have within the Volume Group can be seen in this part of the output:

Free PE / Size 165 / 660.00 MiB

In the above example we only have 660 MB to allocate to LVMs within the turnkeyVolume Group. So if we want to extend the root LV we'll have to first extend the VG backs it up.

Volume Groups group together Physical Volumes. That's why they're called Volume Groups. This command will show us which Physical Volumes have been registered into LVM, and to which volume groups they have been assigned:

In this example we only have one Physical Volume (the /dev/sda2 partition) in the turnkeyVolume Group.

Extending a Logical Volume

Bottom line: if the underlying Volume Group doesn't have enough free space, to extend the Logical Volume you'll first have to extend the underlying Volume Group by adding another Physical Volume to it.

In VMWare you could either create a new virtual hard disk device to add to the volume group, or extend an existing virtual hard disk device, create a new partition with cfdisk, and add the new partition to the Volume Group:

In general, I think it's a good practice to partition the system stuff and big data separately, but it's also more complex to setup and maintain, which is why TurnKey defaults to one big root partition.

If you install from the ISO the di-live installer allows you to setup a more advanced configuration if you want. TurnKey is Ubuntu under the hood so any partitioning scheme you would use for Ubuntu would also work with TurnKey. You may have to do some reconfiguring though (e.g., creating new logical volumes, moving data over, configuring mount points in fstab, etc.)

Regarding Amazon EC2, it lets you do exactly what you want via EBS (Elastic Block Store), which are high-speed SAN backed virtual storage devices that can be created and attached to an EC2 server instance on the fly. The Hub makes it very easy to use this functionality. You should try it.

I don't have immediate need for this info and have only just given it a quick scan (rather than a proper read) but appreciate it never the less. I will get back to this and have a good read as LVM is a bit of a mystery to me (I get the basic idea but it still seems a bit esoteric). I'm sure that many others will really appreciate it too.

Last week I extended my Physical Volume in VMWare but ran into the block of not being able to expand the LVM. I missed the "middle part" about Volume Groups. I will study and Test. The Webmin module sounds good (for newbs like me).

Expanding the physical volume itself was pretty easy in VMware (use the Thin format), but unlike in windows, VMWare does not have an easy way to work with Linux Partitions after that - at least that I could find. The methodologies above will be more than helpful.

oh, Though i am a newbie for linux. I am using Ubuntu from last two years but
in GUI mode. Abobve partitioning theory ,i found it more complex.can you help me
how to partition in linux Ubuntu/Redhat using command line.
Thanking you

So any sort of copying mechanism eg dd, rsync, etc. But probably easiest of all would be to do a TKLBAM backup of your appliance and do a clean install as you desire (no LVM if that's what you want) and restore the data in. Personally I'd test your backup before you destroy the current machine though, just in case something isn't quite right.

Out of interest why would you want to do that anyway? LVM takes a bit of getting used to but IMO it's way cool!

I was trying "dd" with not very much luck (you know, 20G could be very much data to do a dirty test). I don't have a TKLBAM account.

TK is a great appliance, but I found some compatibility issues with Eucalyptus. First (but not only) is the partitioning of the disk. Eucalyptus is expecting /dev/sda1 while TKL is giving /dev/mapper/turnkey-root as the root filesystem. In general, KVM support for TKL would be a great feature, I think.

But I have heard some good things about it. I personally use ProxmoxVE and find it really good. TKL installs to KVM no worries (from ISO) and I have also converted lots of images to run under OVZ (PVE has both). Theoretically the TKL VM images should be able to be imported into KVM but I have only played with it once and dind't have any joy (I didn't try real hard because it's pretty quick and easy to install from ISO). But I agree a KVM image that could be easily imprted would be a plus.

dd is pretty slow but I have successfully dd'd up to 250GB images over a network (SHH) successfully on a number of occasions. That's how I migrated my physical Win2K3 server to a KVM VM. I just used a live CD and dd'd the HDD to a .raw image and KVM picked that up fine. But as I say that was with PVE not Eucalyptus so obviously YMMV.

Well, I'm not very experienced with Eucalyptus or KVM, but I've seen two many issues related to the "Community" version of Eucalyptus not seen in "Enterprise", too bad.

I'm very tempted to drop Eucalyptus in favor of any other virtualization platform (OpenStack, i.e.) or oVirt, when fully available. I don't use OpenVZ, so I see a great issue in using ISO instead of full installed templates like TKL, but it seems to be the only chance by now.

When I talk about KVM support, I am thinking of virtio drivers preinstalled and an XML file, what would be absolutelly amazing to spread TKL for LIBVIRT/KVM users.

ProxmoxVE seems impressive and very straightforward! It's great, but I'm thinking of an EC2 compatible API without loosing optimizations in every VM format. Eucalyptus is not the right option, since it seems centered in GNU/Linux images under Xen, no way of having Windows if you don't have Enterprise Edition.

I run TKL vanilla under KVM (on PVE) and my (anecdotal) experience has been that it seems close to bare metal performance - OVZ performance is even better (although perhaps with VirtIO drivers KVM would be equivalent?) Win is another story though! Without VirtIO drivers disk I/O can be noticably sluggish, especially under load. I haven't noticed much difference with the networking drivers though.

I understand the desire for EC2 compatability. I think OpenStack is probably the future in that regard but i guess time will tell. OTOH via the Hub using a TKLBAM backup I can migrate from KVM/OVZ/VirtualBox/bare metal to an AWS instance very easily (the Hub supports auto restore of a backup to EC2).

Anyway, good luck with your search and let us know if you find something good! :)

I appreciate the conveniance of an LVM configuration but I've hit a few problems 'in production', normally in an abnormal power loss situation. As the OS detacts a 'IO failure' (reported by mount when attempting to resuce the drive), the machine doesn't boot. Someone needs to go in and reactive LVM and run a fsck before it'll boot. None of the LVM tools are available in a failed boot state so it becomes necessary to boot using another image or something.

Is there any way to support lvm+encryption for truecrypt installation? This could be particularly usefull when administrator of different vms have access to the host (the hypervisor) in order to backup, restart (whatever) their own virtual appliance. If each vm is encrypted, an admin of a virtual will not be able to read and understand the content of another.

But it is not supportted OOTB so you'd need to configure this manually on each guest (although perhaps you could script it to somewhat automate the process).

My suggestion would be to have a look at ProxmoxVE. It allows the configuring of users and groups which each can have certain levels of control/access on a per vm, or per host/node basis. It also allows TKL (and other Linux distros) to run under OVZ (which gives you 97-99% performance of bare metal) or KVM (which supports Windows and other OS).

The link you gave me looked really promising, and while I was downloading the Ubuntu image I scrolled through the thread finding this post (page 9 third from the bottom)

Re: ReadyNAS Data Recovery - VMware recovery tool

by doyley86 » Fri Dec 28, 2012 1:19 pm

Guys I have been struggling with this for months, I have found a simple easier way of restoring all my files using some free software called DiskInternals Linux Reader you can download it free from here:http://www.diskinternals.com/linux-reader/

it finds your drive straight away and allows you to copy off all your data! Hope this helps.

Cheers

It's just a small windows program but it reads my LVM without any problems, and now I'm backing everything up nice and easy.

I will save the VMware trick for another catastrophe - for I'm pretty sure there will be more like this one to come.

That's a whole other issue then. My advice to start with would be to take an image of the drive before doing anything. Ideally I like to image to a same or larger size drive. dd is the go, or ddrescue if there are hardware or data corruption issues.

Otherwise I'm not much help. I had a HDD fail on me some time ago and I managed to recover some of the data (about a quarter) by writing a new super block, but I don't recall how I did it... Sorry...

Two helpful things I want to add which I found out during my lvm "studies" as well

The PE's are really nice (from vgdisplay command) and give you some very fine tuned control if you want it. For example if you want to make sure to use all of the free space available, specifying a number such as "1G" or "10G" may not do it.

But I'm sure if you search on google you'll find plenty of info. Keep in mind that TKL v12.x is based on Debian Squeeze and I'm sure you'll find something. Hint: I think you are after user quotas using LVM

Thanks Jeremy, I will search on google about that information. My plan is use around 8 disk (usb disk) of 1 tera, and then use that 8 disk connect in RAID mode, mode mirror (2 disk mirrored=1 tera for 4 users), and I think turnkey is very powerfull tool for that aplication.

I tried using the webmin lvm tool, but then I read your post. Your explanation was the best I've seen yet. I followed and everything worked like a charm. I did have to reboot as you said might happen. Also note, 1. issuing resize2fs may take several minutes 2. for me webmin disk usage side bar shows the original free space now consumed - odd but no big deal.

I had kept aside a good chunk of my hard disk for installing other linux distros. But then was in immediate need of some space to my current home lv. I was worried that I might screw up (As I have the habit of doing so :P) trying to expand my vg. Plus I am new to lvm. I found your article bookmarked it and kept it aside for sometime till now when I really had to do something about the space requirement. But when I went through your article the flow became clear and even cleared many of the doubts I had regarding lvm.